Advertising and media images that encourage girls to focus on looks and sexuality are harmful to their emotional and physical health, a new report by the American Psychological Association says.

The report, released Monday, analyzed some 300 studies over the past 18 months. It included a variety of media, from television and movies to song lyrics, and looked at advertising showing body-baring doll clothes for pre-schoolers, tweens posing in suggestive ways in magazines and the sexual antics of young celebrity role models.

The researchers found such images may make girls think of and treat their own bodies as sexual objects.

"The preponderance of evidence suggests a cause for concern in these sexualized images and the mental health outcomes for girls," says task force member Tomi-Ann Roberts, a psychology professor at Colorado College in Colorado Springs.

Individual studies have found problems related to eating disorders, low self-esteem and depression, but Roberts says there hasn't been a body of work that illustrates how these problems are "directly linked" to sexualized images in ads and popular media. The group recommends more research on girls since the bulk of the studies reviewed dealt with teens and young women.

"It's fair to say, were we to do these same studies on younger girls, you would expect to find the same results, but we have to do the studies," says Sharon Lamb, a clinical psychologist and associate professor at Saint Michael's College in Colchester, Vt., who served on the task force.

The panel defined sexualization as occurring "when a person's value comes only from her/his sexual appeal or behavior, to the exclusion of other characteristics, and when a person is sexually objectified, e.g., made into a thing for another's sexual use."

The report cites Bratz dolls, in particular, for "sexualized clothing such as miniskirts, fishnet stockings and feather boas."

"Although these dolls may present no more sexualization of girls or women than is seen in MTV videos, it is worrisome when dolls designed specifically for 4- to 8-year-olds are associated with an objectified adult sexuality," the report says.

Isaac Larian, CEO of Bratz doll manufacturer MGA Entertainment, based in Van Nuys, Calif., says he "adamantly disagrees" with the report's assessment of the dolls. The company has sold more than 125 million worldwide in the seven years the dolls have been on the market, he says.

"These are the clothes that are worn if you go to schools anywhere in the USA," Larian, a father of three, says. "They are not sexy. Bratz dolls are caricatural plastic dolls. They don't even look like real human beings. They're cartoonish."

The report also notes another toymaker dropped plans to release a line of dolls modeled after the Pussycat Dolls (a musical group known for revealing costumes and sexy lyrics) following a campaign last year against the planned dolls.

Ann Pellegrini, an associate professor at New York University who writes about the sexual politics of American childhood, and who was not associated with the report, says she is concerned about what she calls "the panic" about the sexualization of children.

"Not that I would deny there is this aggressive marketing to children, but there is a deep moralization around it," she says. "I do think girls and women are still profoundly objectified when it comes to sex, but there may well be some things that look like objectification that are being experienced by girls and young women that feel empowering."

She says someone of an older generation might view today's teen-age fashions as too-revealing, but the teen may not see being proud of her body as objectification at all.

The task force urges parents, school personnel and health care professionals to counter sexualization with images of girls in settings that are not viewed as sexual.